jadmt
ignore button user
if max psi on tire is 80psi I would not set it to 88psi. Seems like the tire manufacturer says 80 max for a reason..
Tire and pressure advice
- Thread starter mrfoamy
- Start date
LandCruiserPhil
Expedition Leader
What tire manufacture will give you the go ahead for 10% over?
Are the tires marked with “REINFORCED” or “EXTRA LOAD”
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For off road I deflate to 26psi because my tire pressure sensor warning will stay on for anything under 25psi. As much of a pain the TPS can be, its nice to have your dash light up when your tire fails because you might notice a slow leak right away. I would not run different front and back because then I would have to carry two spares. I mean its not too big a deal to run with an odd tire for a temporary solution, but I would not like the idea of the odd tire when I am 2 days into the bush, maybe not that big of a deal, but something to consider.
A lot of good advice and I recommend going to a Ford forum as well to see if you can find something there. When it comes to TPMS and weights the vehicle is as important as tires and load. I'm running a Ran 2500 diesel and my dash warnings used to alert at 70psi. Had it recalibrated to 50psi but that is very specific to a heavy cummins engine.
That's the sort of comment I was hunting for...again, I asked the wrong question. PLUS, I got off my lazy behind and weighed the truck both axles so now I can get minimum highway pressures from the tire pressure charts. My guess is that the 25psi is a good place for deflation, but I get very nervous when I see how the sidewall bulges as it approaches that pressure. So what is the highest speed you dare when at 25psi??? And the Outside Diameter is nearly the same for both brands so I'm not concerned about the spare, only unpredictable handling. Any unpredictable handling comments???
IdaSHO
IDACAMPER
Only comment I have is about side walls and heat.
The Load F tires will have significantly stiffer sidewalls than the E.
When aired down to a similar contact patch, the F will require a lower pressure, and will generate heat faster.
So keep an eye on the sidewalls, and tire temps, regardless of how low you drop the PSI.
Keeping an eye on tire temps alone will help you figure out just how fast you can go at the low PSI.
Personally, when aired down with my rather heavy setup, I keep it under 35mph, all the while keeping an eye on tire temp data.
The Load F tires will have significantly stiffer sidewalls than the E.
When aired down to a similar contact patch, the F will require a lower pressure, and will generate heat faster.
So keep an eye on the sidewalls, and tire temps, regardless of how low you drop the PSI.
Keeping an eye on tire temps alone will help you figure out just how fast you can go at the low PSI.
Personally, when aired down with my rather heavy setup, I keep it under 35mph, all the while keeping an eye on tire temp data.
LandCruiserPhil
Expedition Leader
GIve my air down system a try. It takes in account vehicle weight, tire size, and tire load rating.
Place a 1" square piece of tubing or solid directly under the tire and air down until each side touches the ground. This will give you a safe starting air down pressure given your set up. I have used my system on tons of vehicles from 4000# - 12500# with excellent results.
Here are a couple I did in your range
The Pictured is a 12.5K CTD flatbed with a FWC 37x12.5x17
This ▼ is an ~8300# Power Wagon with a small FWC 35x12.50x17
For my own I tend to like to run at little lower, pictured is the same truck above running at 18psi
As for driving air down I try to keep it under 45mph on both dirt and tarmac FLAME ON!
AbleGuy
Officious Intermeddler
Sounds like some very helpful advice, so thx....but for the completely clueless like me, how exactly are you monitoring tire temps?
IdaSHO
IDACAMPER
On my Superduty, I shut the OEM TPMS system off, in order to run lower than OEM spec pressures.
I use a very simple and inexpensive external TPMS setup, that also monitors temps.
Lots of variants out there, all of which are import made, but are effective and seemingly reliable.
Like this...
Great, I just ordered that since using my hand to sense temperatures seems too primitive. Have you checked the numbers against a thermal sensor? And how warm/hot is too hot? 150˚F?
IdaSHO
IDACAMPER
Don't be too concerned about actual numbers. Valve stem types can only be so accurate.
Being on the end of the valve stem, they seem to be more accurate at slow speeds than high.
My theory is the faster wheel speed cools the little sensors, making the readings lower than actual.
Regardless, like any gauge, they are a reference, to be used as a relative point, in order to see trends.
Watch for dramatic temp variations between different tires, as that is evidence of a problem.
With some use, you will get a decent idea of typical operating temps.
This will also vary greatly upon ambient temp.
Being on the end of the valve stem, they seem to be more accurate at slow speeds than high.
My theory is the faster wheel speed cools the little sensors, making the readings lower than actual.
Regardless, like any gauge, they are a reference, to be used as a relative point, in order to see trends.
Watch for dramatic temp variations between different tires, as that is evidence of a problem.
With some use, you will get a decent idea of typical operating temps.
This will also vary greatly upon ambient temp.